The present invention relates to an adjustable wrench which is able to change the one-way-wrenching direction of the adjustable wrench during repeated wrenching operation for a work piece.
FIGS. 11 and 12 show a conventional adjustable wrench 8 having a main body 81. A jaw section 82 extends from one side of the main body 81, while a grip 83 is pivotally disposed at the other end of the main body 81. A slidably movable jaw 84 is disposed in a slide way 811 of the main body 81. The movable jaw 84 has a push block 841 protruding out of the main body 81. One side of the front end of the grip 83 inside the main body 81 has a driving section 831 for pushing and driving a slide block 85 to disengage a toothed section 851 thereof from or engage the toothed section 851 with a toothed section 842 of the movable jaw 84. When the grip 83 is wrenched clockwise in a direction of the figure, the slide block 85 is driven to engage with the movable jaw 84 and the jaw section 82 of the main body 81 and the movable jaw 84 cooperatively clamp a work piece 9 (such as a bolt and a nut) and rotate the same. When the grip 83 is counterclockwise wrenched, the slide block 85 is moved away from the movable jaw 84. Therefore, when the main body 81 is driven by the grip 83, the movable jaw 84 will be forced away by the work piece 9 to idle, whereby when repeatedly wrenching the adjustable wrench 8, the work piece 9 can be only one-way rotated.
The work piece 9 can be one-way rotated by means of repeatedly wrenching the above adjustable wrench 8. However, when it is necessary to reversely rotate the work piece 9, (for example, in order to control the nut and bolt to have unified pre-load, the nut is often first tightened and then untightened by one third cycle) a user needs to take up and separate the adjustable wrench 8 from the work piece 9 and re-adjust the position of the movable jaw 84 and then reversely fit the adjustable wrench 8 onto the work piece 9 so as to reversely wrench the work piece 9. Such procedure is quite troublesome. In the case that the work piece 9 is a bolt for adjustment, the user will have to continuously repeat the above procedure to adjust the work piece 9.
It is therefore a primary object of the present invention to provide an adjustable wrench in which the projecting rail of the movable jaw and the projecting section of the slide block are together inlaid in the slide channels of the main body. A bolt is passed through the concave face of the movable jaw and the semicircular groove of the slide block with the bolt screwed with the thread of the concave face for driving the movable jaw to move along the slide channels. A movable retaining block is disposed on one side of the top end of the grip opposite to a leaning section of the slide block. The retaining block can be switched, whereby when the grip is wrenched in different directions, the retaining block abuts against and pushes the leaning section of the slide block so as to move the movable jaw toward the jaw section of the main body for clamping and wrenching a work piece. When the retaining section does not abut against and the leaning section and the grip is wrenched, the slide block and the movable jaw are shifted by the work piece to make the main body idle. By means of switching the retaining block, the one-way wrenching direction of the adjustable wrench during repeated wrenching operation for the work piece can be changed.
The present invention can be best understood through the following description and accompanying drawings wherein: